Lock washer



Feb. 2, 1937; E, D COWLIN 2,069,402`

' LOCK WASHER Filed June 29, 1935 3 Sheets-Sheet l- 12 I .f2 ,9a/g,

By W( (L Arron/mrs Feb. 2,; H937; E, Q COWLHN 2,669,402

LOCK. WASHER Filed June 29, 19:55 s sheets-sheet 2 F/ G. /Z l G. /i

Arro/PA/frs Patented Feb. 2, 1937 UNITED STATES PATENT OFFICE 2,069,402,Loox `WASHER of Ohio Application June 29, 1935, Serial No. 29,125

14 Claims.

My invention particularly relates to lock washers for use where tightconnections are necessarily maintained, for instance, maintainingelectrical conductivity in radio and other electrical apparatus. Theinvention also lends itself for use in many other fields where a morepositively locking washer is required than any concerning which I aminformed.

It is an object of the invention to provide an eiiicient, long-lifewasher of the aforementioned type which will be simple in construction,eco- `nomical to manufacture, non-entangling with other like washers,and which will lend itself to automatic assembling. The principle of thein'- vention may be applied to washers of all sizes and gauges andintended for either light or heavy duty.

My improved washer is essentially a ring plate or a conical open-endedshell, either closed or 20 split, which, in unstressed condition, hasnonplane or rolling faces, the washer being provided withoutwardly-tapered locking projections or nibs upon either or both faces.Against these locking projections either the nut or the bolted seat, orboth, abut and press when the washer stock is compressed by thetightening of the nut. Conical or approximately conical lockingprojections are preferred as being the strongest form of projection forresisting distortion in operation 30 and for transmitting stressesuniformly to the main body of the washer. Preferably, these lockingprojections have exterior gripping edges formed by piercing entirelythrough the washer stock when forming the projections.

Washers having a wavy contour in unstressed condition are a verydesirable type and are described and shown inv the instant application.

Preferably, the aforesaid locking nibs are located on the crests of therespective waves of the washer faces and preferably centrally of theinner and outer peripheries of the ring plate of whichthe Washer ismade. Preferably, also, the locking projections are equally spaced onefrom the other, i. e., the contour of the washer faces is of uniformwavy appearance. Locking projections may be" applied, with certainadvantages, adjacent the inner or the outer periphery of the washer,thus forming a series of half-conical locking projections along eitheror both peripheries.

The washers may be made by stamping the blanks from flat sheets orstrips or, in the case of split ring washers, by coiling strip materialand forming and cutting the blanks one at a time from the coil. 'I'helocking projections may be of various types and shapes, and may haveopenended or closed outermost tip terminal portions,

i. e., the punches with which the projections are formed in the die mayentirely pierce the blank or simply distort the same suiciently to formthe projection out of the blank material without breaking through thelatter. The preferred form of washer, however, is obtained by entirelypiercing the blank when forming the locking projections, thus creatingexterior gripping edges around the openings thus formed in theprojections. Some of the suitable forms of projections are: conical,tapered projections with rounded terminals, and projections havingrather at main body members with sharply deflected central terminalportions.

The annexed drawings and the following description set forth in detailcertain means illustrating my invention, such means constituting,however, only a few of many forms in which the principle of theinvention may be embodied.

In said annexed drawings:

Figure 1 is a plan view of a fragment of sheet material from which threeblanks for one form of my improved washer have been stamped;

- Figure 2 is a top plan of one form of my improved wavy-type washer;

Figure 3 is an edge View of the washer shown in Figure 2;

Figure 4 is a bottom plan of the washer shown 30 in Figure 2;

Figure 5 is a vertical section, upon an enlarged scale, taken in theplane indicated by the line 5-5, Figure 2;

Figure 5, is afragmentary view, similar to 35 Figure 5 but on a greatlyenlarged scale Figure 6 is an enlarged developed edge view, taken fromthe plane indicated by the line 6 6, Figure 2;

Figure 7 is a top plan of a wavy-type washer 40 having a modied form oflocking projection;

Figure 8 is an edge View of the washer shown in Figure 7;

Figure 9 is a bottom plan of the washer shown in Figure 7;

Figure 10 is an enlarged section, taken in the plane indicated by theline Ill- |0, Figure 7;

Figure 11 is a top plan of a wavy-type washer having locking projectionsof the general type o shown in Figures 2, y3, and 4,` except that in thelatter figures, a washer is shown in which the punch with which theprojections were made pierced through-the blank material; whereas, inFigure 11 is shown a washer in which the punch g did not pierce throughthe blank material when the projections were made;

Figure 12 is an edge view of the washer shown in Figure 11;

Figure 13 is an enlarged section, taken in the plane indicated by theline i3-i3, Figure 11;

Figure 14 is a plan of a terminal plate suitable for use in radio andanalogous apparatus, which terminal plate is integrally formed with onetype of my improved wavy-type lock washer;

Figure 15 is an end view of the terminal plate shown in Figure 14;

Figure 16 is a view illustrating the' use of one of the closed-ringwavy-type lock washers in a nut and bolt assembly, the full-line showingof the washer therein being a partly compressed condition of the washer,for instance, when the washer has been compressed into a substantially-iiat condition; the broken line showing of the washer in said figurebeing that of a still further compression which deiiects those sectionsof the washer which were originally convex upwardly into a form convexdownwardly, and vice versa;

Figure 17 is a plan view of washer stock wound into a helixthavingmaterial for three split-ring washer blanks, there being indicated indotted line the plane of a proposed cut by which one blank will beremoved from the` assembly, there also being indicated by dot-and-dashline a plane which is perpendicular to the axis of the helix, and by abroken line the extension of the upper normal helical surface or planeof the coiled assembly, it being noted that thev stock is wound at anangle to the perpendicular plane less than the angle made therewith bythe normal helix so that the stock is wound under an initial tension;

Figure 18 is a side view of the assembly shown in Figure 17;

Figure 19 is a plan view of a washer of the split-ring type whose bodymember is a wavy contour inunstressed condition, this washer beingprovided with one form of my improved locking projections, the washerends being so related as to provide for non-entanglement of the washerswhen shipped or stored in bulk, even if the washers have no positivenon-entangling outwardly-projected end portions;

Figure 20 is an edge View of the washer shown in Figure 19;

Figures 21, 22, and 23 are views illustrating, somewhat more in detailthan is shown in Figure 16, the effect upon one of the closed-ringwavytype lock washers in a nut and bolt assembly, as the nut istightened upon the bolt from its initial engaging position with thewasher to its fully tightened position; Figure 21 Showing the conditionswhen the nut exerts no pressure, Figure 22 showing the conditions whenthe washer is semi-compressed, the washer being under partial tension,and Figure 23 showing the Yconditions when the Washer is fullycompressed, the waves of the washer having become reversed in positionsunder the conditions ,shown in Figure 23;`

Figure 24 is a plan view of a fragment of a steel strip and shows theprogressive formation therein of a plurality of washer blanks of asplit-ring shell type, which are pressed out of the steel strip intowavy formation with locking projections before they arelsevered from thestrip in split individual washer blanks;

Figure 25 is a plan of one of the completely pressed washer blanks madefrom the strip shown in Figure 24;

Figure 26 is a fragmentary plan of a metal ribbon pressed so as, whencut into separate lengths, to form' a wavy washer blank of thesplit-ring shell type of each of the severed strip portions;

Figure 27 is a plan of the completed split-ring wavy shell type ofwasher made from one of the steel strip pressed portions of Figures 24and 26, after the blank has been rolled into conical shape;

Figure 28 is a side View of the washer shown in Figure 27;

Figure`29 is a vertical section through a washer of the type shown inFigure 28 in position upon a suitable cap or machine screw Which is heldby the washer against turning or loosening in a suitable seat with whichthe screw engages, the view showing the fully tightened position of thescrew and the compressed condition of the Washer;

Figure 30 is a plan section, taken in the plane indicated by the line30-30, Figure 29;

Figure 31 is a plan section, similar to Figure 30, but showing thecondition of the washer before the screw has been tightened;

Figure 32 is a top plan view of another form of shell-like washer whichhas been blanked out from sheet metal and formed into the completedwasher, it being of the closed shell type and having an irregular orwavy top portion and a round-regular bottom hole that will not interferewith the threads of the screw or bolt;

Figure 33 is a bottom plan of the washer shown in Figure 32;

Figure 34 is a side view of the washer shown in Figure 32, the viewbeing taken from the planes indicated by the line 34-34, Figure 32;

Figure 35 is a plan view of a at blank which may be used for forming theclosed-shell type of washer shown in Figures 32, 33, and 34;

Figure 36 is a side view of a washer of the character shown in Figures32, 33, and 34, in which substantially the upper half is of wavycontour, and is provided with the locking projections, and substantiallythe lower half is of circular cross-section for smooth engagement withthe outer surface of the screw or bolt; and

Figure 37 is a plan view of a flat blank which may be used for formingthe type of washer shown in Figure 36.

Referring to the annexed drawings in which the same parts are indicatedby the same several numbers in the different views, steel sheet materiali is shown in Figure 1, from which, by one method of making my improvedwasher, three washer blanks have been stamped which lby suitableoperations are formed into complete washers, such as the washer 2,Figure 2, which is one form of the washers embodying my improvements.This washer 2 is of wavy contour. clearly seen in Figure 3, havingcrests 3 and intermediate troughs 4, four such crest portions beingshown, for purposes of illustration, and an equal number of alternatetrough portions, these crests and troughs being preferably of uniformdimensions, as shown in Figure 3, but not necessarily so. The number ofcrests and troughs may also vary within desirable and suitable limits.The top and bottom faces, 5 and 6, respectively, of the washers 2, arepro'- vided with extending nibs l, the same forming locking projections,in the stressed condition of the washer, as 4hereinafter fullyexplained; these nibs 'l being located, preferably, at the outermostpoints of the crests 3 and comprising, in

formed by the entire piercing of the blank with the punch when makingthe projections 1.

In Figures 7, 8, 9, and 10, is shown a washer l 2, of essentiallysimilar body structure to that of leo the washer shown in Figure 3, butin which the locking projections II are of substantially semisphericalcontour and not formed with terminal apertures, such as illustrated bythe apertures I in Figures 5 and 5*.

The washer 22, shown inA Figures 1l, 12, and 13, is similar to thewasher shown in Figure 3, except that the locking projections I2 are notprovided with the apertures I0 and the terminal portions I3 of theprojections I2 are of substan` tially conical construction. i

In Figures 14 and 15, I show the application of one form of my improvedwasher toa resilient terminal plate I4, suitable for use in elec-Itrical and radio apparatus, which plate I4 is provided with a hole I5adapting the plate I4 for attachment vto an electrical conductor, theplate I4 also being formed integrally with an enlarged washer portion I6havinglocking projections II of substantially the same construction asthose in Figure 8.

In Figure 16 Ishow the application of a washer 2 or 22 intermediate thebase of a nut 36Yengaging a bolt 31, and any suitable supporting seat38, the washer 2 being intended to serve securely to lock the nut 36 andthus prevent the latter from backing off the bolt 31 after the nut hasbeen tightened as desired. In the full line showing of the washer inFigure 16, the nut 36 has been partly tightened resulting in acompression of the washer, by reason of the engagement of the nut 36with the upper locking projections 1, to a substantially flat positionof the Washer body. In other Words, the upwardly convex portions of thewasher body have been deflected downwardly and the up` wardly concaveportions straightened, so asto compress the washer into a substantiallyplane structure. Thereafter, a further tightening of the nut 36 resultsin further deflecting the aforementioned upwardly convex portions of thewasher below the normal central horizontal plane of the washer body, andin deforming the aforementioned upwardly concave portions into upwardlyconvex portions, as indicated by the broken line showing in Figure 16. Afull tightening of the nut 36 would result in forcing the respectivewasherv portions opposed to the projections 1 against the working facesof the nut 36 and the seat 38, respectively, thus preventing furtherrotation of the nut. As the nut 38 is tightened, the upper lockingprojections 1 or I2, whose terminal portions I8 or I3 may, if desired,

be of a hardened structure, dig into the opposed face of the nut 36,preventing the backward rotation of the latter during use, and also thelower locking projections 1 dig into the naterial of the supporting seat38, particularly if the seat 38 is of comparatively soft material suchas wood. The seat 38 may, of course, be of any suitable material that isdesired for the particular duty involved. Certain methods of producingthe from the material of the washer blank, will result in themselves inhardening the terminal portions 9 and I3 without any special hardeningoperation.

Figures 21, 22, and 23 further illustrate the conditions shown in Figure16, which have just been described. In Figure 21, the washer 2 is inunstressed condition, and in Figure 23, the washer 2 is shown in fullystressed condition. It will be notedthat the crests 3 and troughs 4 arerespectively reversed in positions in Figure 23 from the positions shownin Figure 2l. Figure 22 sh`ows a semi-compressed condition of the washerwherein the wavy contour thereof has been changed to a substantiallyfiat shape. The effect of reversing the curves by compression of thewasher into the condition shown in Figure 23 is to provide a constanttension over a wide reactive range, thus fully' protecting the assemblyagainst looseness, the reversibility of the curves under pressureeffecting the maintenance of a constant non-fatiguing tension under thescrew, bolt, or nut, and the locking projections resisting any tendencyof the screw, bolt, or nut to back off.

The washers shown in Figures 19 and 20 are of the split-ring type.One'suitable method of making such washers comprises coiling washerstock into a helix and cutting the individual Washers one at a time fromthe coiled assembly, as illustrated in Figures 17 and 18. These lattergures also illustrate one method of so forming split-ring washers as torender them non-entangling in storage or shipping, and to that end,Washer stock I8, preferably of keystone crosssection, is coiled upon a.mandrel by suitable tools into a helix, the coiling being as close aspossible and under an initial tension which may be produced asillustrated by the plane lines in Figure I1. The plane 22 designates theactual winding plane. 23 designates the plane of the upper normalhelical surface in which the stock I8 would lie just previously to beingwound, if no axial tension therein were induced. The plane 24 designatesthat planewhich is perpendicular to the axis of the helix and whichpasses through the place in the upper or outermost surface of the stockwhere it is bent or flexed out of the normal helical formation. Sincethe stock I8 as a whole is bent or flexed at the place of bending, thelower surface of the stock as viewed in Figure I1, or that surface ofthe stock which adjoins thelast-formed convolution of the coiled stock,bears a relation to the normal helical formation similar to that of theupper surface of the stock. Therefore the angle at which the stock I8 iswound is less than that of the normal helical formation but notsubstantially less that of the respective planes perpendicular to theaxis of the helix and passing through the place of bending in the upperand lower surfaces of the stock and hence the stock is wound underinitial tension. In' this winding or coiling, and as is well-known f/ tothose skilled in the art, the keystone crosssection is altered and arectangular cross-section of the material of the coils of the helix isobtained. The coils I1 are cut from the helix one at a time to form theseparate washers I9. As illustrated in Figures 17 and 18, the thirdWasher from the incoming stock I8 is removed after each successive coilI1,is formed. I illustrate three coils l1 in Figure 17, of which thelowermost coil will be removed by cutting in the plane 20 to form theblank of an individual washer I9. This locking projections 1, such asforming the samecut in theplane 20 is made so as to form the washerblank with as narrow a gap 2| between the adjacent washer ends as ispracticably possible, particularly when the ends of the completed washerare not provided with positive outwardly- `directed non-entanglingprojections.

When the washer blank is cut from the coiled helix along the plane 20,the axial tension is relieved and the adjacent ends of the blank snapslightly inwardly relative to each other so as to overlap slightly inthe plane 2|), if the ceiling has been perfectly close. In other words,the prolongation of the bottom helical surface of the upper washer endacross the gap 2| would substantially enter or lie slightly below theupper helical surface at the lower end of the washer. This constructionprovides a non-entangling washer in a plane pattern or, in other words,with ends of uniform cross-section. Within the limits specified, viz.,from the normal helical plane 23 to the plane 24 which is perpendicularto the axis of the helix, the washer stock I8 may be placed undertension when coiled so as to provide, after the individual washers aresevered, varying amounts of overlap of the adjacent washer ends or a.registry of the washer ends. Also, the size of the gap 2| and theprecise closeness of coiling govern the nature of the desirable relationof the washer ends to each other to prevent entangling. Preferably, thevarious factors which result in the nal relationship of the washer endsare coordinated so as to provide a condition at the washer ends in whichthe extension of the lower substantially helical surface at the upperend of the washer would contact with the upper substantially helicalsurface at the lower end of the washer, and the improved split-ringwasher herein shown, viz.the washer of Figures 19 and 20, is soportrayed.

After the washer blanks have been cut from 40 the helix shown in Figure17, they are subjected to suitable operations to form the improved formof washer shown in Figures 19 and 20.

In Figures 19 and 20, I illustrate a split-ring washer 3| of the wavytype, in unstressed condi` tion, which is provided upon its upper andlower faces 32 and 33,-respectively, with a plurality, three as shown,of semi-spherical locking projections 34. The washer 3| is provided witha gap 2| between the washer ends which is relatively small, the formingof the washer by the ceiling and cutting process shown in Figures 17 and18 having been under such suitable tension as to cause the helicalsurfaces of the adjacent ends substantially to register, resulting in anon-entangling type of washer by reason of the smallness of the gap 2|and the nature of the relation of the adjacent washer ends to eachother.

It is the form and relationship of the washer ends which results in thenon-entangling feature thereof, so that portions of the washer blankremote from the ends may be distorted, when producing the form of washershown in Figure 20, without destroying the non-entangling feature of theends which has been produced by the making of the washer blanks in themanner illustrated in Figures 17 and 18.

The action of the washer of closed-ring type in practice is as follows:When the nut is screwed down upon the washer interposed between the nutand the supporting seat, the lower face of the nut engages the uppermosttips of the upper locking projections and, upon a. further tightening ofthe nut, moves these projections downwardly, causing the adjacentportions of the washer body to deflect downwardly. This results in aresilient but positive pressure of the upper projections against thelower face of the nut and an equally resilient pressure of the lowerprojections against the face of the seat toward which the nut is beingscrewed. A continued tightening of the nut will deect the severalportions of the washer body which are opposed to the several projectionsagainst the faces of the nut and seat and thus prevent further rotationor tightening of the nut.

The form of washer which has locking projections with apertures, such asthe aperture I in `terminal 9, Figures 5 and 5u, possesses verydesirable holding properties in that the piercing of the metal to formthe aperture I provides roughened edges IIJ' which exercise a bitingaction upon the nut and seat.

The resilient pressure of the locking projections against the faces ofthe nut and seat is not destroyed by extreme tightening of the nut. Thisis a particularly important improvement in washers of this class. Thisresilient pressure is maintained in the extreme tightened position ofthe nut and no permanent distortion of the Washer takes place as aresult of the extreme tightening of the nut due to the fact that thewasher material is not stressed beyond its elastic limit by the utmostpermissible deflection thereof.

The outermost tip or terminal of the locking projection, whichwithstands the severest strain, is entirely surrounded by metal on allsides which supports and strengthens it and reinforces its lockingaction.

As hereinbefore mentioned, the tips of the locking projections whichrequire the greatest wear-resisting properties can be hardened, or maybe hardened even in fabricating, since the punch and die compact andtoughen the metal. However, any excessive hardness or brittleness at theterminal -tips will not result in their breakdown inasmuch as thesurrounding metal provides a uniformly distributed support for thesetips.

My improved washer has no parts thereof which are likely to break oifand become en- "meshed in the machinery or other apparatus in which itis used. The improved stamped washer has a smooth inner and outerperiphery which will not injure the hands of the mechanic in assembly.Also, the stamped washer utilizes all the metal between the bolt holeand the outer circumferenceof the washer, no portion of the washer beingcut away, so that a very substantial construction is provided which alsoprovides a uniform bearing surface for the nut. Furthermore, my improvedwasher has no inwardly-projecting tongues or other parts to becomeentangled in the threads of the bolt with which the nut engages.

In my improved washer, thinner metal can be used than has been used forwashers of equivalent duty inasmuch as the load is applied centrally ofthe washer and uniformly around the periphery of the washer.Furthermore, the individual deflecting portions of my improved washer byreason of the complete support provided therefor are, in fact, beamswhich are supported at each end, rather than mere cantilevers anchoredto the body of the washer, as is true when such complete support is notprovided.

'This improved washer assures a definite pressure of the lockingprojections on the opposed faces of the nut and seat for a wide range ofrelative positions of the nut and seat, and also possesses a follow-upor a continuing tensioning action, thus maintaining contact of thelocking projections with the base of the nut in the event of anaccidental partial rotation of the nut.

By reason of the provision of three or more locking projectionsextending vequal distances from each face of my 'improved washer, thelatter will Alie flat on whichever side it is laid, thus making itadaptable for automatic assembly.

In the use of my improved washer as a part of a terminal clip orequivalent device in electrical and radio and other similar apparatus,eiiicient and continuous electrical contact is assured by reason of thefollow-up tension of the washer.

I direct particular attention to the fact that when spring tension isexerted upon the nutby the deflection of a portion of the Washer body,the said washer body is supported on two spaced points and the tensionbeing exerted on the nut is at a point intermediate the spacedsupporting points. i

Referring particularly to Figures 24-31, inclusive, I therein illustratea form of split-ring wavy type of washer which is a conical shell, andis intended for use between the flat head of a countersunk cap ormachine screw and the wall of the conical hole in the seat which thescrew engages. Of the many methods of forming such conical shell typesplit washers, I illustrate two, one in Figure 24, and the other inFigure 26. In forming these washers I first press out of metal stripsthe washer formation with suitable locking projections, and then severthe individual portions into washer blanks which are subsequently rolledinto conical shape.

In Figure 24, I show a metal strip 42 of substantially the width of thediameter of one of the desired blanks, and this strip 42 is pressed soas to form laterally-extending locking projections 44 with the terminalapertures 44' and to form the desired wavy contour of the completedwasher, after which the individual blank portions are cut from the strip42 to form separate washer blanks 43, such as illustrated in Figure 25.These blanks can be rolled into completed conical-washers, such aswasher 49, Figures 27 and 28.

In Figure 26, I illustrate the use of a metal strip 45 of ribbonformation, and of a width equal to the vertical height of the desiredconical shell-type washer. This ribbon strip 45 is also first pressed soas to form the desired wavy contour and the locking projections 46,after which ribbon lengths suitable for the desired size of washer arecut from the ribbon strip 45 along the lines 41, so as to provide ablank 48 having one edge longer than the opposite edge, whereby theblank 48 can be rolled into `a conical split shell which shall serve asthe completed washer 49, Figures 27 and 28. One preferred arrangement oflocking projections 44 consists of a single series positioned in a planeperpendicular to the plane containing the axis of the washer, theprojections laterally extending from the washer body and extendinginwardly and outwardly alternately.

In Figures 29, 30, and 31, I illustrate the use of one of my improvedsplit-shell type of washers with a screw 50 having a flat conical head5|, the screw 50 engaging a suitable seat 52 having a conical recess 52withinwhich the conical head 5| may be countersunk. Figure 3|illustrates the condition of the washer 49 before the screw 50 has beentightened, and Figures 29 and 30 illustrate the condition of the washer49 after the screw 50 has been tightened. It will be noted from aninspection of Figures 29 and 31, in connection with Figure 30 which is aplan section through Figure 29, that the wavy contour of the washer 49has been reduced in depth of crests and troughs in tightening the screw50 and that the terminals of the locking projections 44 alternatelytightly engage the wall of the seat recess 52 and the outer surface ofthe screw head 5| to prevent the backing off or loosening of the screw50. l

Referring particularly to Figures 32, 33, 34, and 35, I therein disclosea closed-shell type of washer 53 formed from sheet metal material. Onemethod of making this closed-shell washer is to stamp out flat blanks54, Figure 35, from sheet steel, and then press or otherwise suitablyformed when the blank 54 is stamped out. When the blank 54 is pressedinto suitable shape for the desired form of completed washer 53, thewavy or desired irregular outline is formed inthe shell body, the latterbeing made of conical formation and, preferably, the wavy or irregularoutline is limited to a top portion 51 of the shell and the lowerportion or, at least the extreme lower portion, is formed of regularcircular crosssection, so that the smaller lower end hole 56 of theshell is round and does not interfere with the threads of the screw orbolt 50. Thus the top of the washer is irregular to set up a tensionover the head 5| of the screw or bolt 50, and the locking projectionsand the roughened edges of the apertured terminals 55' engage thecountersunk surface of the seat 52 and the undersurface of the head 5|of the screw or bolt 50.

Referring particularly to Figures 36 and 37, I therein disclose aclosed-shell type of washer 58 formed from sheet metal material, and ofa character similar to the washer shown in Figures 32, 33, and 34,except that the washer 58 is of the desired wavy irregular outline forsubstantially its upper half, and is of regular circular cross-section,for substantially its lower half, locking projections 59 being formed inthe wavy upper half of the shell body. One method of making the type ofwasher 58 is to stamp out flat blanks 60, Figure 37, from sheet steel,and then press or otherwise suitably form the blank 60 into thecompleted washer 58. The lower half of the washer 58 of regular circularcross-section provides means for smoothly and effectively engaging theouter surface of the screw or bolt and` permits the convenient turningof the latter, when tightening, without blocking or damaging engagementofthe washer therewith by reason of wavy or irregular lower portions ofthe washer intersecting the path of movement of the screw or bolt as itis being turned. Preferably, the locking projections 59 have aperturedterminals 6| formed with roughened or biting edges 62.

What I claim is:

1. A lock washer comprising a split ring' plate of wavy contour in theunstressed condition of the plate, said plate having end portionsbrought into juxtaposition to prevent washer entanglement in shipping orhandling, at least one of the faces of the plate being provided with aplurality of spaced outwardly-extended locking projections of the plate.

2. A lock washer comprising a spring plate having an aperture foraccommodating a screw or bolt, the plate being of wavy contour andhaving an outwardly-extended locking portion on the convex side of eachof a plurality of the plate waves upon both washer faces, said waves,under compressive force applied to the locking portions, beingchangeable in position over a range of positions from upper convexformation to upper concave formation and vice versa.

3. A lock washer of annular wavy formation including a plurality ofspring sections having substantially rigid outwardly-extended lockingportions on the convex sides of the washer waves, said waves, undercompressive force applied to the locking portions, being changeable inposition over a range of positions from upper convex formation to upperconcave formation and vice versa.

4. A lock washer comprising a spring plate having an aperture foraccommodating a screw or bolt, the plate being of wavy contour andhaving outwardly-extended locking portions disposed on the crests of theplate waves, said waves, under compressive force applied to the lockingportions, being changeable in position over a range of positions fromupper convex formation to upper concave formation and vice versa.

5. A lock washer comprising a spring plate having an aperture foraccommodating a screw or bolt, the plate being of wavy contour andhaving outwardly-extended locking projections with rounded terminalportions and disposed upon the convex sides of the plate waves, saidwaves, under compressive force applied to the locking projections, beingchangeable in position over a range of positions from upper convexformation to upper concave formation and vice versa.

6. A lock washer comprising a spring plate having an aperture foraccommodating a screw or bolt, the plate being of wavy contour andhaving conical locking portions outwardly-extended in planesperpendicular to planes intersecting the washer axis at right angles,said locking portions being disposed on the convex sides of the platewaves, said waves, under compressive force applied to the lockingportions, being changeable in position over a range of positions fromupper convex formation to upper concave formation and vice versa.

'1. A lock washer comprising a spring `plate having an aperture foraccommodating a screw or bolt, the plate being of wavy contour andhaving outwardly-extended locking portions on the convex sides of theplate waves whose bases are entirely surrounded by the lbody of theplate, said waves, under compressive force applied to the lockingportions, being changeable in position over a range of positions fromupper convex formation to upper concave formation and vice versa.

8. A lock washer comprising a spring plate having an aperture foraccommodating a screw or bolt, the plate being of wavy contour andhaving outwardly-extended locking portions on the convex sides of theplate waves, said locking portions having apertured terminals, saidwaves, under compressive force applied to the locking portions, beingchangeable in position over a range of positions from upper convexformation to upper concave formation and vice versa.

9. A lock washer comprising a spring plate having an aperture foraccommodating a screw or bolt, the plate being of wavy contour andhaving outwardly-extended locking portions on the convex sides of theplate waves, said locking portions having rough apertured terminals,said waves, under compressive force applied to the locking portions,being changeable in position over a range of positions from upper convexformation to upper concave formation and vice versa.

10. A lock washer comprising a spring plate having an aperture foraccommodating a screw or bolt, the plate being of wavy contour andhaving outwardly-extended locking projections on the convex sides of theplate waves, said locking projections being chambered and having annularterminal portions, said waves, under compressive force applied to thelocking projections, being changeable in position over a range ofpositions from upper convex formation to upper concave formation andvice versa.

11. A lock washer comprising a split ring plate having non-entanglingend portions, the plate being of wavy contour and havingoutwardly-extended locking portions disposed upon the crests of aplurality of the plate waves upon both faces of the washer, said waves,under compressive force applied to the locking portions, beingchangeable in position over a range of positions from upper convexformation to upper concave formation and vice versa.

12. A lock washer comprising a spring plate having an aperture foraccommodating a screw or bolt and having at least one of its faces ofwavy contour in the unstressed condition of the plate, the wavy plateportion having a plurality of outwardly-extended locking projectionsdisposed on the crests of the face waves and whose bases have circularperimeters and are entirely surrounded by the body of the plate.

13. A lock washer comprising a spring plate having an aperture foraccommodating a screw or bolt, the plate faces being of wavy contour inthe unstressed condition of the plate, said plate faces each having anoutwardly-extended conical locking nib on theconvex'side of each of aplurality of the face waves whose base is entirely and symmetricallysurrounded by the body of the plate.

14. A lock washer comprising a spring plate having an aperture foraccommodating a screw or bolt, the plate being of wavy contour in itsunstressed condition, at least one of the plate faces having a pluralityof outwardly-extended locking projections disposed on the crests of thewaves, the basesvof said locking projections being entirely surroundedby the body of the plate.

EUGENE D. cownm.

